Carnica: the grey alternative

by David Yanke, appeared in May 2005 Issue of the New Zealand Beekeeper magazine

Like it or not, Carniolans (carnica) are back, and this time they are here to stay. So you may as well make the most of it, but to do that, you first have to know a little bit about them.

There are still more questions than answers when it comes to Carniolans and how they will fit into New Zealand beekeeping. I will try to address the most frequently asked questions, but because some of these questions are far more easily asked than answered, you may feel dissatisfied at the end of this process. I'll start with the easy questions first.

What are they?

Carnica (Apis mellifera carnica) is a race of European honey bee, very closely related to the Italians (A.m. ligustica), and said by some to be a grey version of the Italian. Also like the Italians, carnica is one of the two best and most widely used honey bees in the modern beekeeping world. It is the bee of the Balkan Peninsula, extending into the Alps, and over the Black Sea up into the Ukraine. Having evolved in the continental climate of south eastern Europe, it is a very hardy bee, showing quick population increase in the spring (to put it mildly), and good production potential. It is a very gentle, quiet bee. The carnica is about the same size and shape as the Italian, but dark, with broad, dense hair bands (tomenta) on their abdomens: it is this pubescence that give carnica its characteristic grey appearance. Exactly how explosive their build-up will be under our spring conditions, and how much swarming this will lead to if not managed properly, are difficult questions with no sure answers at the moment.

How did they get here, again?

Cases have been documented of carnica queens having been brought into New Zealand in the past, and it is almost certain that there were illegal importations of carnica as well. The number of queens involved was small, and no serious effort was made to create a viable breeding population of carnica, so inevitably they were swallowed up into the New Zealand gene pool, overwhelmed by the mating advantage of the feral population of A.m. mellifera, and by the commercial preference of the time for yellow bees.

For decades then, except for the myths and legends of illegal imports, fortress New Zealand stood firm. No legal importations of live bees or genetic material occurred until a small breach of the defences in 1988, and again in 1989, when I brought in a small amount of Italian-type semen from the Western Australian Bee Breeding Program. Besides injecting some new material into the New Zealand gene pool, the purpose of these importations was to soften up the defences for carnica. A group of us thought that it would be a positive thing to introduce carnica into New Zealand. It would give beekeepers here a choice in what bees they ran, and it would let our live bee exporters obey the first law of business: letting us supply our customers with what they really want. I couldn't possibly count the number of times I was asked if I could supply carnica queens, and could only reply, "You can have any type of queen you like, as long as it is yellow".

Anyway, the defence softening did not work. We tried and failed several times during the 1990s to get carnica semen in. Once we came as close as having the semen on its way to the airport in Germany when MAF had to pull the plug because of a successful last-minute attack by those in the industry opposed to the importation. They were worthy opponents: as determined as I was to get carnica in, they were equally determined to keep carnica out. Each failure, though, was a small step towards eventual success, but it was hard to see this at the time. Things were gradually getting done: an initial risk analysis was performed; ERMA declared carnica not to be a new organism; and an initial Import Health Standard was developed. These initiatives were still not enough, as the Import Health Standard (IHS) was just too tough and proved unworkable. It took the arrival of varroa to create the will that finally found the way to make it happen.

Although we were very unlucky to be invaded by varroa, we were fortunate that so many had gone before us. We knew from overseas experience that managing varroa only gets more difficult with the passage of time, as resistant varroa remove the easy-to-use weapons from our arsenal. Look at the situation in North America now, where, 20 years down the track, varroa is more deadly then ever. We knew that increasing the varroa tolerance of our bee stocks was the only viable answer. MAF realised this as well, and they knew that tapping into the varroa tolerance work being done overseas was the surest and quickest path to significantly varroa-tolerant bees.

A new risk analysis was carried out, which can be viewed at www.biosecurity.govt.nz/pests-diseases/animals/risk/index.htm#genetic. It concluded that only importations of semen could be managed so as to pose a negligible risk of introducing an exotic pest, disease or unwanted Genetic Material. The 'unwanted Genetic Material' referred to the Africanised Honey Bee and the Cape Honey Bee. The Import Health Standard For The Importation of Carniolan Honey Bee (Apis mellifera carnica) Semen into New Zealand from Germany and Austria was drafted, and became operational in 2004. Slovenia may be added to the IHS in 2005. The IHS may be viewed atwww.biosecurity.govt.nz/imports/animals/standards/honeybeesemic.spe.htm

Importations to New Zealand

Using this IHS, a total of 100 doses of semen were imported from one institute in Germany and another in Austria in early June 2004. A second importation, totalling 140 doses, arrived in early August 2004 from the same two institutes, as well as from another German institute. Both importations were more successful then I dared hope.

I went to Europe and picked the semen up myself for the first importation, and carried it back on my person. While I was at the German institute at Kirchhain I had a good look at the stock from which the semen was sourced and was very impressed. The bees were beautiful, very gentle and very quiet. I saw carnica in a side-by-side trial with Primorsky queens straight from the USDA facility in Baton Rouge, Louisiana, headed by Dr Thomas Rinderer.

The Primorsky, or Russian bees, have become the standard by which varroa tolerance is measured. Primorsky is the region in the far east of Russia from where the USDA researchers sourced their varroa-tolerant stock. From the mid-1990s they continued to import selected queens from this region. They have stopped now, and are working with what they have. The reason these Primorsky bees are so tolerant is because they have had it for decades longer than any other place, and they are thought to be ground zero for the global explosion of Varroa destructor. Russian settlers took European Honey Bees, Apis mellifera, to this region, which was a frontier with the Asian Honey Bee, Apis cerana. Varroa jacobsoni was a pest of cerana, but would not reproduce in mellifera worker brood so posed no threat until the classic species jump occurred, and a mutant mite that could rampantly reproduce on mellifera, now known as Varroa destructor, made the leap and started the global invasion of European honey bees.

Back to the trial. All of the colonies were more than 12 months into the trial without treatment when we inspected them. While you could find mites in the drone brood in most of the colonies, all were still healthy, and all still produced a crop in that second year. To my eye the Primorsky stock had fewer mites; in fact, in one colony we had to search very hard to find even one mite in the drone brood. The data showed that the best carnica were as varroa tolerant as the average Russian, but the Russians had some serious problems. They were far more nervous and nasty than carnica, much like our mellifera crosses here, and they produced little honey, but their worst trait was their swarming. Without exception the Primorsky bees started trying to swarm early, and they kept trying through until late summer.

For the second importation, in August 2004, the semen from the three institutes was brought together into one consignment and airfreighted to me. I know that moving people and things around the globe is no big deal anymore, but sitting down and inseminating queens with semen that had been collected on the other side of the world only a couple days before was a real buzz. That thrill has continued right through this past season as I got to work with the results of those importations.

Both of the importations last year, and the ones to come this year, are the cornerstones of the Varroa Tolerance Improvement Project (VTIP) being run by Daykel Apiaries. The goal of VTIP is to provide usefully tolerant breeders for sale - both carnica and Italian. We are doing this by maintaining and improving the Italian closed population we already have developed, and by establishing a viable breeding population of carnica; then maintaining and improving both populations, with varroa tolerance being the most heavily weighted selection criteria.

The foundation stock for the carnica population were very carefully selected Italian queens that had been inseminated with pooled semen from the closed Italian population. For the first importation, 10 breeders were used, and 10 daughters from each of the breeders were inseminated with the semen I brought back in early June. The semen was sourced from two institutes. The Austrian institute was in Lunz, established by Dr F Ruttner, and has been breeding carnica for decades. The German institute in Kirchhain is well known for their carnica breeding work. (Dr Ralph Bûchler is the head of this institute. I would like to take this opportunity to acknowledge his support over the years, without which I might well have given up, and surrendered to fortress New Zealand.) The semen from each institute was from several drone sources so I pooled each separately, and inseminated half of the virgin queens with Austrian semen, and half with German. All went well, and the queens were laying as quickly as they would have in the middle of summer. I had emerging workers before the end of June.

I tried to do my best to select breeders for the second importation in August, but was obviously limited in what I could do because of the short time between the importations and the fact that it was the middle of winter. I did morphometric testing by measuring the cubital index of the workers of each of the queens. Cubital index is the ratio of the lengths of two veins around the cubital cell in the wings of bees. It is a very distinctive racial characteristic. Mellifera has the lowest, and carnica has the highest of the European races, so the higher their cubital index, the higher their score. I waited as long as I could, and tested their hygienic behaviour as well. So using the morphometric and hygienic scores, and a good dose of gut feeling, I selected 15 breeders. These breeders were pure Italian, but they carried pure carnica semen in their spermathecas. Again, I reared 10 daughters from each of these breeders. These daughters were F1 hybrids: 50% Italian and 50% carnica in their genetic makeup.

(An interesting aside: when you rear drones from these F1 queens, 50% of the drones are pure Italian and 50% are pure carnica. This is because the drones are haploid; that is, they have only one set of chromosomes representing one half of the queen's genetic makeup. So when the queen produces her eggs, the process sees her double strands of DNA unzip, with the carnica strand going to one gamete, and the Italian strand going to another.)

Back to the second importation. Semen was again sourced from Lunz and Kirchhain, with different drone sources being used at both institutes than were used in June, and semen was also sourced from another German institute in Mayen. The semen from each institute was again pooled separately, and 144 virgins were inseminated at the end of the first week in August. All went well, and once again, the queens started laying surprisingly fast for that time of the year.

It was such a relief for things to go as well as they did. To source semen from the Northern Hemisphere means that you have to rear virgins outside the normal time for doing such things, to say the least. I always thought I could do it, but there was always that niggling doubt, and I knew there was the potential for disaster.

The queens from the second importation were introduced into the test units in mid-September, equalised, and treated for two weeks. Treatment was removed, marking the beginning of the evaluation period that ended in mid-February 2005, when mites started taking their toll on some of the test units, especially the Italian control colonies. They were treated again, and boards put under the test units to monitor mite fall over a seven-day period. Frames of brood were also taken, and frozen for later mite counts to measure the level of brood infestation. Evaluations are ongoing for measurement of the usual variables such as temperament, hygienic behaviour and honey production, as well as the morphometric measurements. Breeder selection will have to be completed by early May 2005, so that I can undertake the breeding work for another importation in early June.

What have I learned so far?

I've learned very little about how carnica will perform under New Zealand conditions. This year has been an experience in hybrid beekeeping and the hybrids have been very impressive. Hybrids are an intermediate bee, however, so they do not cast much light on true carnica behaviour. The hybrids produced more honey and they had fewer mites. In the test units, only three of the 20 Italian control colonies were still healthy; the rest had dying bees and brood to some degree when treated at the end of the evaluation period. While 25 of the remaining 80 hybrid test colonies were still perfectly healthy, and most of those had very few mites, a couple had less than 20 mites after the seven-day mite drop. I was very impressed and concluded that our Italian bees are mite magnets, because the sudden increase in mite numbers in February wasn't simply reproduction, it was invasion, and the Italians took on many more mites than their share. Although the performance of the hybrids exceeded my expectations, nevertheless they were hybrids, and their performance could be largely be put down to the effect of heterosis (hybrid vigour).

Besides the evaluation of the hybrids in the test population, I have had feedback on the commercial hybrids I produced this season. I sent out thousands of naturally mated hybrid queens, about 70% were F1 hybrids, and about 30% were F2 hybrids. The queens I produced in the spring mated with mostly Italian drones under the conditions of our most difficult spring ever, and the appearance and performance of their colonies reflected that. By mid-January the weather had come right, and most of my drone sources were much more carnica-like, and I was very happy with the hybrid queens I was sending out. The feedback was encouraging and mostly positive, and supported what I was seeing. In summary, the hybrids, especially the F1s, proved to be a very good commercial bee: very prolific in their brood rearing, very good honey producers, and of acceptable temperament. Nothing that was unexpected. A large-scale beekeeper in the Bay of Plenty (who has hundreds of the hybrids in his outfit) recently told me that while carrying out his autumn treatment, he has noticed that the hybrids have significantly fewer mites than his Italian colonies.